transaction problem with entity framework 4

I'm trying to implement a transaction with entity framework 4. From what I've read, the code below is correct. The SaveChanges works fine but as soon as I hit the first ExecuteFunction call I get the following exception:

The underlying provider failed on Open. ---> System.Transactions.TransactionManagerCommunicationExc开发者_JS百科eption: Network access for Distributed Transaction Manager (MSDTC) has been disabled. Please enable DTC for network access in the security configuration for MSDTC using the Component Services Administrative tool.

I've logged on to the database server and I don't see a service called Distributed Transaction Manager but I do see Distributed Transaction Coordinator and it is started. I'm not sure what I need to change to allow this to work. Anyone know? Thanks.

Here's the code.

using (var h = new WhaleEntities(ConnectionHelper.DBConnectString))
{
    using (TransactionScope ts = new TransactionScope())
    {
        h.Sites.AddObject(s);
        h.SaveChanges(SaveOptions.DetectChangesBeforeSave); 
        retval = s.SiteID;

        h.ExecuteFunction("UpdateSiteInterfaceList", new ObjectParameter("pSiteID", retval), new ObjectParameter("pList", "10"));
        h.ExecuteFunction("UpdateSiteInterfaceRequiredList", new ObjectParameter("pSiteID", retval),new ObjectParameter("pList", "Email"));
        h.ExecuteFunction("UpdateSiteInterfaceAlwaysShownList", new ObjectParameter("pSiteID", retval),new ObjectParameter("pList", "10"));
        h.ExecuteFunction("UpdateSiteInterfaceAlwaysRequiredList",new ObjectParameter("pSiteID", retval),new ObjectParameter("pList", "Email"));

        ts.Complete();

        //changes must be accepted manually once transaction succeeds.
        h.AcceptAllChanges();
    }
}

See here: How do I enable MSDTC on SQL Server?